Evaluate f(9) and f(9.1) and use the results to approximate f '(9). (round your answer to one decimal place.) f(x) = x(5 − x)

Need on this geometry question. explain how you did it.

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39